Neck gasket



The sole FIGURE is an elevational view of a neck gasket.

A top plan view, a bottom plan view, a left side view, and a right side view of this neck gasket are omitted because such views are non-claimed subject matter.

The broken lines showing portions of a wall illustrate environmental subject matter that forms no part of the claimed design. 

CLAIM What is claimed is the ornamental design for a neck gasket, as shown and described. 